U.S. Pat. No. 4,001,742 entitled "Circuit Breaker Having Improved Operating Mechanism" describes an early operating mechanism for high ampere-rated circuit breakers. A more recent description is found within U.S. patent application Ser. No. 08/228,761 filed Apr. 18, 1994 entitled "A System for Resetting High Ampere-rated Circuit Breaker Operating Springs".
With such high ampere-rated circuit breakers, a pair of main contacts is employed to carry steady state circuit current and a separate pair of arcing contacts is required to handle the large currents that occur in an overcurrent circuit interruption. The so-called "contact depression" whereby the movable contacts press against the stationary contacts within both the main and arcing contacts, is carefully adjusted in the final stages of the circuit breaker assembly process. The current-carrying components are usually dismantled and the tolerances that exist with the operating mechanism components is compensated by adjustments of individual components.
In a high speed assembly process utilizing automatic assembly equipment in some stages of assembly, the efficiency of the process is decreased by the time required to dis-assemble and re-assemble these components.
One purpose of the invention is to set the contact depression in accordance with the component tolerance in the final stages of the assembly of the current-carrying components without involving a large number of components or requiring the expenditure of substantial manufacturing time.